Tuesday, December 31, 2013

The Rodent Filter

My current house is a delapidated mobile home I bought for $800, gutted, and am completely re-doing the inside using lumber from the old house and other scrounged and beautiful materials. 

I'm only at the land three days a week and was having terrible problems with rats and mice getting between the walls, chewing up wiring and generally making a mess and even getting into the house and chewing up rugs and so forth. Very destructive little creatures. I didn't want to poison them, and I hate traps that sometimes maim but don't kill. So I built a pole barn around the mobile home. 

The pole barn
provides shade so the mobile home stays relatively cool in summer; it provides a roof to catch rainwater; I can put greenhouse plastic on the north side in winter to keep out the cold wind. But the best thing is that I put wire on the outside of the pole barn and keep cats inside it, half of whom are polydactyl which (I believe, having watched them in action) makes them better at catching rodents. Many dung beetles moved in to take care of the cat poop, and I've seen no sign of rodents in or near my home, or for that matter unpleasant bugs. Fortunately, I am also very fond of cats and very much like to sit in front of a fire with a purring cat on my lap. I'm going to try to attach a photo of the rodent filter.

Sunday, June 2, 2013

Increased CO2 leads to greening of Earth



[1] Satellite observations reveal a greening of the globe over recent decades. The role in this greening of the ‘CO2 fertilization’ effect – the enhancement of photosynthesis due to rising CO2 levels – is yet to be established. The direct CO2 effect on vegetation should be most clearly expressed in warm, arid environments where water is the dominant limit to vegetation growth. Using gas exchange theory, we predict that the 14% increase in atmospheric CO2 (1982–2010) led to a 5 to 10% increase in green foliage cover in warm, arid environments. Satellite observations, analysed to remove the effect of variations in rainfall, show that cover across these environments has increased by 11%. Our results confirm that the anticipated CO2 fertilization effect is occurring alongside ongoing anthropogenic perturbations to the carbon cycle and that the fertilisation effect is now a significant land surface process.

Monday, May 27, 2013

Patogen that caused Irish Potato Famine in 1840's Identified

I am listening to an audio book about the 1840's famine in Ireland (The Graves Are Walking by John Kelly), so this article caught my attention:


An international team of scientists reveals that a unique strain of potato blight they call HERB-1 triggered the Irish potato famine of the mid-19th century
It is the first time scientists have decoded the genome of a plant pathogen and its plant host from dried herbarium samples. This opens up a new area of research to understand how pathogens evolve and how human activity impacts the spread of plant disease.
Phytophthora infestans changed the course of history. Even today, the Irish population has still not recovered to pre-famine levels. “We have finally discovered the identity of the exact strain that caused all this havoc”, says Hernán Burbano from the Max Planck Institute for Developmental Biology.
For research to be published in eLife, a team of molecular biologists from Europe and the US reconstructed the spread of the potato blight pathogen from dried plants. Although these were 170 to 120 years old, they were found to have many intact pieces of DNA.
“Herbaria represent a rich and untapped source from which we can learn a tremendous amount about the historical distribution of plants and their pests – and also about the history of the people who grew these plants,” according to Kentaro Yoshida from The Sainsbury Laboratory in Norwich.
The researchers examined the historical spread of the fungus-like oomycete Phytophthora infestans, known as the Irish potato famine pathogen. A strain called US-1 was long thought to have been the cause of the fatal outbreak. The current study concludes that a strain new to science was responsible. While more closely related to the US-1 strain than to other modern strains, it is unique. “Both strains seem to have separated from each other only years before the first major outbreak in Europe,” says Burbano.
The researchers compared the historic samples with modern strains from Europe, Africa and the Americas as well as two closely related Phytophthora species. The scientists were able to estimate with confidence when the various Phytophthora strains diverged from each other during evolutionary time. The HERB-1 strain ofPhytophthora infestans likely emerged in the early 1800s and continued its global conquest throughout the 19th century. Only in the twentieth century, after new potato varieties were introduced, was HERB-1 replaced by anotherPhytophthora infestans strain, US-1.
The scientists found several connections with historic events. The first contact between Europeans and Americans in Mexico in the sixteenth century coincides with a remarkable increase in the genetic diversity ofPhytophthora. The social upheaval during that time may have led to a spread of the pathogen from its center of origin in Toluca Valley, Mexico. This in turn would have accelerated its evolution.
The international team came to these conclusions after deciphering the entire genomes of 11 historical samples of Phytophthora infestans from potato leaves collected over more than 50 years. These came from Ireland, the UK, Europe and North America and had been preserved in the herbaria of the Botanical State Collection Munich and the Kew Gardens in London.
“Both herbaria placed a great deal of confidence in our abilities and were very generous in providing the dried plants,” said Marco Thines from the Senckenberg Museum and Goethe University in Frankfurt, one of the co-authors of this study. “The degree of DNA preservation in the herbarium samples really surprised us,” adds Johannes Krause from the University of Tübingen, another co-author. Because of the remarkable DNA quality and quantity in the herbarium samples, the research team could evaluate the entire genome of Phytophthora infestans and its host, the potato, within just a few weeks.
Crop breeding methods may impact on the evolution of pathogens. This study directly documents the effect of plant breeding on the genetic makeup of a pathogen.
“Perhaps this strain became extinct when the first resistant potato varieties were bred at the beginning of the twentieth century,” speculates Yoshida. “What is for certain is that these findings will greatly help us to understand the dynamics of emerging pathogens. This type of work paves the way for the discovery of many more treasures of knowledge hidden in herbaria.”

Saturday, January 19, 2013

Solar Roof Panels


Monday, January 7, 2013

Protecting the Home From Wildfire

We've had a respite from worries about brush and forest fires over the last few weeks, with cooler temperatures and rain. My Australian husband and I have been keeping up with the bush fire situation in Australia, which reminds me that I need to fire-proof my country place to the best of my ability, before weather conditions get hot and dry again, as they undoubtedly will.

The closest I've come to a forest fire was in 1996 when an electric wire fell and started a fire at Altamira. Fortunately, I saw it happen, and The McMahan Volunteer Fire Dept got there within a few minutes (which reminds me, I need to send in a donation to them), but not before it got large enough to be very scary. The most frightening thing, to me, was seeing the fire jump from tree top to tree top. Pine trees were the very worst. There would be a tree standing in relatively isolation, say, 15 feet away from its nearest neighbor, looking just like it always had. Then, suddenly, explosively, it would burst into flame -- the whole canopy all at once.

I have planted 3 pine trees at the Berry Farm and a few junipers, mainly because the grasshoppers were killing everything else I tried to plant. Both of these species burn readily -- I've observed that the pine is especially bad. Dead juniper wood and leaves burn easily, but green branches not so much, at least in my experience. There are no trees at all within 45 feet of my house, but there are 2 large old junipers in the yard of the old homestead (I need to tear the old homestead down, because it is beyond redemption), and I planted a few more near the pole barn, as a wind break.

I'm wondering ... if I keep all the lower branches pruned from the large old trees and keep the young junipers cut low, would it be OK to keep them? Or should I remove them? Or should I let them grow tall and keep the lower branches trimmed back? It's the leaves and small branches that burn, not the trunks. It's not all that easy to get a cedar log to burn. I used to throw a cedar log on my fire every evening, for the fragrance. I'd always need to get the fire going with some other kind of wood first. Some other windbreak possibilities are: native plum thicket, yaupon holly (which I've heard burns readily but which, in my experience, is not nearly as likely to burn as pine), Japanese ligustrum (a very well adapted exotic which, I have to say, the grasshoppers love to eat), Chinese photinia (a well-adapted exotic), Russian olive or eleagnus (a well adapted exotic that produces berries in cooler climates, but it tends not to fruit in central Texas), and hardy olive trees, which tend to form thickets and do very well in my garden in San Antonio but which are frost sensitive below 25 degrees F.

Sunset Valley, Texas has published a nice article on plants that don't tend to catch fire easily. I'm just east of the Hill Country, but many of the same plants grow on my land. Sunset Valley recommends:

Unfavorable tree don’t have to be removed, just keep branches pruned to 10 feet about the ground
   Firewise Plant Recommendations for your Region



Texas Persimmon                                                              Desert Willow                                                         
            Crape Myrtle                                                                     Bigtooth Maple                                               
            Mexican Sycamore                                                            Black Walnut                                                    
Texas Ash                                                                           Mexican Plum
            Texas Mountain Laurel                                                      Texas Smoke Tree
            Red Maple                                                                           Silver Maple
            Boxelder                                                                               Pecan
            Bitternut Hickory                                                                 Shagbark Hickory
             Pignut Hickory                                                                     Mockernut Hickory
             Sugarberry                                                                            Hackberry
            Netleaf Hackberry                             


                Red Yucca                                                                          China Rose
                Tea Rose                                                                            Pomegranate
                Winter Honeysuckle                                                          Coral Berry
                Strawberry Bush                                                                Eastern Coral Bean
                Indigo Bush                                                                        Common Buttonbush


                Purple Leatherflower (Cover for small birds)           Coral Honeysuckle (Hummingbirds)

                Snapdragon Vine (Fruits eaten by birds)                     Engelmann Daisy (Seed-eating birds)
                Turk’s Cap (Attracts hummingbirds)                           Maximilian Sunflower (Seed-eating birds)
                Golden-eye (Provides nectar to bees)                            Rose Pavonia (Attracts butterflies)
                Indian Blanket (Attracts butterflies)                             Coreopsis (Attracts butterflies)
                Purple Coneflower (Seed-eating birds)                        Sweet Violet (Attracts butterflies)


                Redtop (Good birdseed)                                                    Black Grama (Wildlife grazing)
                Hairy Grama (Wildlife grazing)                                   Buffalo Grass (Drought tolerant)
                Weeping Lovegrass                                                           Plains Muhly (Wildlife grazing)
                Bush Muhly (Wildlife grazing)                                      Tobosa

I do like the junipers for their berries and fragrant wood. When my father was lying on his death bed, I took a juniper branch to his bedside on Christmas day and lit it on fire in a ceramic container (over my mother's strenuous protests). My father was quite moved by this. He said the fragrance of the burning juniper took him back to his youth when he and his father used to go on camping trips into the Hill Country west of Austin. He said it was one the of the nicest Christmas gifts he'd ever received.

Finally, in support of the widely maligned juniper, a quote from Edward Abbey:

“The fire. The odor of burning juniper is the sweetest fragrance on the face of the earth, in my honest judgment; I doubt if all the smoking censers of Dante's paradise could equal it. One breath of juniper smoke, like the perfume of sagebrush after rain, evokes in magical catalysis, like certain music, the space and light and clarity and piercing strangeness of the American West. Long may it burn.”

A reminder from a couple of years ago, when I watched helplessly as the Bastrop fire approached Altamira: Wildfires in Texas

Sunday, January 6, 2013

ARC - Animal Road Crossing

ARC—Animal Road Crossingis an interdisciplinary partnership working to facilitate new thinking, new methods, new materials and new solutions for wildlife crossing structures.
Our primary goal is to ensure safe passage for both humans and animals on and across our roads. We do this through supporting the study, design and construction of wildlife crossing structures throughout North America.
ARC builds bridges in other important ways: We reconnect landscapes and wildlife habitats that have been split apart by our road systems; we reacquaint people and wildlife, helping drivers to be aware of the habitats our roads interrupt and the animals that use these places; and through these strategies, we reaffirm the need for humans and animals to coexist in the landscapes we call home.
Situated at the intersection of science and design, ARC is a forum for creative collaborations and surprising synergies.

I have not read extensively on this. I wonder if organizations such as ARC place attractive plants close to the animal crossing bridges and culverts, to encourage the animals to use them.
There are large herds of deer near my country place. At night, I don't like to go over 45 mph on the stretch of road between my place and the Interstate 9 miles away.